Kangaroo has a built-in benchmark option in "-check" that will benchmark the number of keys/second for your hardware, but with two things to note. First, you have to pass -gpu to get benchmarks for your GPU, otherwise you'll just get CPU benchmarks. Second, this is the part of the code in Check.cpp that actually does the benchmark:
// Check on ComputePublicKeys
for(int i = 0; i<nbKey; i++) {
Int rnd;
rnd.Rand(256);
priv.push_back(rnd); <--- [1]
}
t0 = Timer::get_tick();
for(int i = 0; i<nbKey; i++)
pts1.push_back(secp->ComputePublicKey(&priv[i])); <--- [2]
t1 = Timer::get_tick();
::printf("ComputePublicKey %d : %.3f KKey/s\n",nbKey,(double)nbKey / ((t1 - t0)*1000.0));
t0 = Timer::get_tick();
pts2 = secp->ComputePublicKeys(priv);
t1 = Timer::get_tick();
::printf("ComputePublicKeys %d : %.3f KKey/s\n",nbKey,(double)nbKey / ((t1 - t0)*1000.0));
To benchmark any other int operation such as add, subtract, divide or multiply, just make a duplicate this snippet at the end, but at [1] you might have to make another array of Ints for binary operations, and at [2] you gotta replace ComplutePublicKey which whatever you're trying to benchmark, such as
(some int)->add(&priv).